class_docstr: Patch a callback output value
  
  Act like a proxy of the output prop value on the frontend.
  
  Supported prop types: Dictionaries and lists.
code: def __setitem__(self, key, value):
      validate_slice(key)
      if value is _noop:
          # The += set themselves.
          return
      self._operations.append(
          _operation(
              "Assign",
              self._location + [key],
              value=value,
          )
      )
  
label_desc: Use image node_id 8 for calling the Patch obj's underlying member method code with example usage: obj.__setitem__(key, value) without return types